The Marchioness, a small pleasure cruiser packed with around 130 partygoers, was sunk with the loss of 51 lives when it was struck by a barge on the River Thames on this day in 1989.
The boat, which had been hired by a young entrepreneur named Jonathan Phang to celebrate the birthday of his business partner Antonio de Vasconcellos, was hit by the dredger Bowbelle near the Cannon Street railway bridge as both vessels headed downriver in the early hours of the morning.
The anchor of the 1,880-tonne barge sliced through the side of the 46-tonne Marchioness, which rolled over and began to capsize immediately; as it did so, the Bowbelle (pictured below) continued forward, pushing the stricken cruiser underneath it and deeper into the water.
The smaller boat was completely immersed in no more than 30 seconds, with most of the victims trapped in its hull. The majority of survivors had been on its upper decks when the collision occurred; police commandeered other small boats to pick them up at the scene.
An investigation found the disaster to have been caused by the poor visibility from each ship's wheelhouse, the fact that both vessels were using the centre of the river and the lack of clear instructions to the lookout on the Bowbelle.
The captain of the dredger, Douglas Henderson, was twice prosecuted for failing to keep an adequate lookout but was acquitted as the juries were unable to reach a verdict on both occasions. However, a coroner's inquest in 1995 found the victims had been unlawfully killed.
Survivors and families of victims campaigned more than 10 years for a public inquiry, which was finally held in the year 2000.
Chairman Lord Justice Clarke’s report blamed poor lookouts on both vessels for the collision and criticised the boats’ owners for failing to instruct and monitor their crews correctly.
Lord Clarke’s recommendations also led to four lifeboat search and rescue stations being set up on the Thames by the Royal National Lifeboat Institution (RNLI) in 2002, as well as changes to laws governing inland waters.